1. Field of the Invention
The present invention relates to a fan and a motor thereof, and more particularly to the fan and motor capable of preventing lubricating oil from being evaporated to outside of the fan and enhancing the combination of a magnetic-conducting device, a shaft, and an oil-sealing structure.
2. Description of the Related Art
Fans are driven by motors to rotate, and properties of the motors determine the quality of the fans. A bearing is also an important element for supporting a shaft in the motor. If the bearing does not provide sufficient lubrication and fixation to the shaft, noise is easy to generate.
Metallic shafts supported by oil-contained bearings are a common skill to extend the operating life of a motor of a fan. For example, FIG. 1 is a schematic sectional view of a conventional fan 1. The fan 1 includes an oil sealing 11, an oil-contained bearing 12, a shaft tube 13, and a metallic shaft 14 supported by the oil-contained bearing 12. The oil sealing 11 is disposed between the shaft tube 13 and the metallic shaft 14.
The oil-contained bearing 12 is metallically casted by metallic particles and lubricating oil is pressurized into voids of the aggregated metallic particles. When the fan 1 is rotated, the lubricating oil held in the voids of the aggregated metallic particles is leaked, thereby lubricating the contact surfaces therebetween. Because of evaporation of the lubricating oil by heat and frictional loss, the function of the oil-contained bearing 12 is gradually diminished after long-term operation. Thus, noise increases and the oil-contained bearing 12 and the metallic shaft 14 begins to stick and malfunction. Although the oil sealing 11 disposed between the shaft tube 13 and the metallic shaft 14 is applied in controlling the loss of the lubricating oil, the lubricating oil still flows out of the shaft tube 13 via the clearance formed between the oil sealing 11 and the metallic shaft 14. Moreover, situated in an environment with long-term vibration, the oil sealing 11 will often loosen and fail, resulting in loss of the lubricating oil.